Automated tape libraries were developed to expedite the selection and loading of magnetic tape reels. One such type of automated tape library resembles an elongate rectangular chamber. Racks of tape reels are provided at selected locations along the interiors of the opposing elongated walls. An interior track runs the length of the chamber between the parallel racks. A reel retrieval/loading device is mounted on a carriage that travels along the track, and is translatable along two rectangular axes in addition to the third axis of the track. The retrieval/loading device is automatically controlled to locate and engage a selected reel in a Cartesian coordinate system, and then transports the selected reel to a target one of a plurality of tape drives. The tape drives are located along the exterior wall of the chamber at windows provided for access to the drives. The retrieval/loading device automatically mounts the selected reel on the target tape drive.
Another configuration for a storage library features a cylindrical chamber, with racks provided along the interior of the circular wall and a plurality of peripheral devices located along the exterior at windows. The retrieval/loading device is positioned in the center of the room and is operated in a cylindrical coordinate fashion.
Magnetic tape cartridges have recently become popular as a unit of storage medium, particularly 8 mm magnetic tape cartridges. Advantageously, magnetic tape cartridges facilitate economic and compact storage of data. With the advent of widespread use of magnetic tape cartridges, the need to provide automatic storage and retrieval systems for such tape cartridges has resulted in a wide range of automated storage and retrieval systems. These storage and retrieval systems suffer from drawbacks such as limited cartridge capacity and also lack of ability to be expanded.
The present invention is directed to reducing the effects of one or more of the problems set forth above. In particular, the present invention provides a mass storage unit for tape cartridges which controllably loads a selected one of a plurality of tape cartridges to and from one of a plurality of magazines into and out of a selected one of a plurality of tape drives by use of a tape cartridge elevator.